Box stacking and conveying mechanism



'7 Sheets-Sheet l March 9, 1943. A. NEJA BOX STACKING AND CONVEYING MECHANISM.

Filed April 28, 1941 March 9, 1943.

Filed April 28, 1941 7 Sheets-Sheet l2 A 7/ /l TTORIVEY March 9, 1943.

A. NEJA` 2,313,478

BOX STACKING AND CONVEYING MECHANISM Filed April 28, 1941 '7 'Sheets-Sheet 3 d 1 1N V'ENT'OR, A y/0056 Aff/a;

A TTORNE Y March 9, 1943. A NEJA 2,313,478'

BOX sTAcKING AND CONVEYING MEGHANISM Filed April 28, 1941 I 7 Sheets-Sheet 4 f- 'ATTORNEY March 9, 1943. v A. NEJA Box sTAcKING AND CONVEYING' MECHANIsM Filed April 28, 1941 '7 Shets-Sheet 5 March 9, 1943. Y ,1 NEJA l 2,313,478

BOX STACKING AND CONVEYNG MECHANISM A TTORNE Y A. NEJA 2,313,478

BOX STACKING AND CONVEYING MECHANISM l March 9, 1943.

Filed April 28, 1941 7 Sheets-Sheet '7 ATTORNEY Patented Mar. 9, 1943 Niran STATES afiaN'Lrk oFPicE,

BOX vSTACKING AND CONVEYING MECHANISM Ambrose Neia, Anaheim, Calif. Application April 28, 1941, Serial No. 390,737

(ci. 214-6) Y i i 18 Claims.

This invention relates to box stacking and. conl i veying mechanism.

At the present time, it is customary in warehouses after a box has been packed with fruit, or

other objects, but for the present assuming fruit,

to stack the boxes one upon the other to a given height and thereafter to move the stack to selected locations within the Warehouse for further distribution.

An object of the present invention is to mechanically stack the boxes to any predetermined height, and thereafter, through suitable conveying means, to move the stacked boxes to any given location.

Another object is the provision of mechanism adapted to stack boxes wherein boxes are sequentially placed upon a conveyor and fed by said conveyor into stacking mechanism, whereby the boxes are stacked one upon the other for any selected number, and after a stacking of the selected number, to move said boxes by suitable I provide a suitable conveyor termed a eeding conveyor, upon which may be placed boxes,

` which have been. lled with various commodities so that the mechanism functions efiiciently andproperly at all times.

Other objects4 of the, invention box stacking mechanism which is inexpensive in cost of manufacture, and capable of producing superior results.

mechanism, automatically functioning, to any designated location.

Another object is the provision of suitable conveying mechanism adapted to feed boxes to a stacking mechanism, and after proper stacking, to provide further mechanism which carries said boxes from the stacking mechanism, so that the sequence of conveying` and stacking is carried on at a rapid rate.

Another object is the provision of mechanism which is simple in character, with the number of working parts reduced to a minimum, which is capable of operating rapidly, and which stacking of boxes or similar objects to a given heightor number is accomplished without the already stacked boxes dropping during stacking, which might result. in injury to any object or objects within the boxes.

With respect to the last named object, it may be stated that fruit, as a rule, is closely packed within its boxes, and if the boxes are roughly handled, the surface of the fruit is often injured, with the result that rot takes place or the fruit is rendered unsalable on the market. It, therefore, is essential in any type of box stacking mechanism, and constitutes an object of the present invention, to provide stacking mechanism which produces minimum jar during a stacking operation oi one box upon the other. It is likewise essential that after the boxes have been stacked, that they be lowered to the conveying mechanism with a minimum of jar, and for the reasons stated.

In the simplest embodiment of my invention,

With the aforesaid objects in view, the invention consists in the novel and useful provision, formation, construction, association andv relative arrangement of parts, members, and features, all as shown in a certain embodiment in.

the accompanying drawings, described generally, and more particularly pointed out in the claims.

In the drawings: Figure 1 is aplan view of the improved stacking and conveying mechanism,

Figure 2 isa fragmentary plan view of certain features of the invention shown in a changed relationship from that of Figure 1,

Figure 3 is a rear elevation of the improved box stacking and conveying mechanism,

Figure 4 is a rear .elevationI of the box stacking and conveying mechanism, and looking in the direction of the arrow 4 of Figure 1, I

Figure 5 is a sectional view on the line 5 5 of Figure l,

Figure 6 is a fragmentary vertical sectional view, similar to that of Figure 5, but Showing certain parts in a changed relationship from that of Figure 5,

Figure '7 is a side elevation, partially in vertical section, on the line -'l of Figure 3,

Figure 8 is a sectional view on the line 3,-8 of Figure 5, and on an enlarged scale of said gure,

Figure 9 diagrammatically illustrates a wiring diagram for controlling motor operation for the box stacking and conveying mechanism,

Figure 10 is a fragmentary, transverse sectional and plan view of a lmodied form of the conveying mechanism,

consist in a Figure 1'1 is a sectional view on the line I I-II of Figure 10,

Figure 12 is a modified form of a member of the elevating mechanism, and,

Figure 13 is a fragmentary sectionalview on the line I3-I3 of Figure 12.

Referring now with particularity to the drawings, and as a brief statement of the invention,

I provide suitable feeding mechanism whereby boxes which have been filled with some commodity, say oranges, are directed to a stacking trough. At the stacking trough, I provide an elevator which receives a box, elevates the box to .a given lposition, whereupon suitable means holds the box elevated, the elevator descending to its initial position and another box may be received thereon, again raised to contact the already elevated box within the stacking trough, and the first and second boxes are then held elevated, the elevator again descending to a lower level, and so on, until a given number of boxes have been stacked one upon the other in the trough.

While any number of boxes may be stacked, still for convenience it is assumed,'in the present invention, that stacks of seven boxes are desired. When the seventh box is to be elevated, suitable mechanism which contacts with the uppermost box of the stack is operated, upon elevation of the last box, to-wit, the seventh. This mechasituated some distance from the mechanism just described, say some place in a warehouse. The discharge conveyor is so constructed and arranged that a length of the same is normally below the level of the top of the elevator duringall the time that boxes are being stacked and untilI a designated number of boxes have been stacked, whereupon through suitable mechanism, this discharge conveyor is elevated for contact with the lowermost box of the stack.

' I have also provided on the feed conveyor suit- Y able mechanism whereby boxes to be fed to the elevator to be stacked in the trough are prevented from bunching, or from an attempted feed. ing to the elevator when the elevator is raised or moving upwardly or downwardly. To this end, I have provided two types of feed conveyors, one of which is constantly in operation, and the other of which operates depending upon the position of a box to be fed to the elevator. A clutch arrangement is provided, said clutch being operated by suitable levers, whereby the clutch is either engaged or disengaged, dependent upon the position of the boxes upon theA two feed conveyors.

.If, for instance, the elevator is in the act of moving upwardly to lift a box, the continuously running feed conveyor has the upper reach thereof dropped below certain supporting rollers for the box, whereby this vfeed conveyor does not move the box. 0n the other hand, if two boxes are too closely placed together upon the conveyors, then through suitable lever arms adapted to contact with the boxes, the clutch is disengaged, which will stop movement of the intermittently oper` ated feed conveyor, the continuously running conveyor at all times being in operation to feed one of the boxes onto the elevaor.

I have provided .a novel .arrangement of switches for controlling the operation of an electric motor, which motor in turn drives through suitable mechanism for raising and lowering the elevator. The arrangement is such that the elevator will always assume a correct downward position at all times, a feature of importance, as any tendency of the elevator to lower and then slightly raise again might change the timing arrangement in such a manner as to directly affect the discharge conveyor. In other words, the discharge conveyor mechanism might not sufriciently raise the same above the top surface of the elevator so that a stack of boxes could be moved from the stacking trough.

Further refinements of the invention consist in suitable pneumatic means for assisting in lowering of the elevator with the filled boxes stacked thereon.

'I'he device for initially feeding boxes, stacking the same, and discharging the same after being properly stacked is designated as an entirety by lI; and said device may have its constituent members, such as the feed conveyor designated as an entirety as 2, the discharge conveyor designated as an entirety by 3, positioned relative to stacking mechanism for the boxes, including an elevator 4, arranged at or below floor level 5. Thus, in the embodiment, boxes already on the floor and packed with a commodity, may be placed upon the feed conveyor 2 to be ushered into the stacking mechanism and particularly upon the elevator I, raised by the elevator a. selected distance so as to sequentially build up a pile or stack of boxes in substantial parallelism within a stacking trough 6. As has been stated in the brief outline of the invention, the boxes, after being stacked to a given number, are moved from the trough by the discharge conveyor 3 at the floor level 5, to a given designated location in a warehouse.

The feeding conveyor 2 (see Figure 1) includes in the present adaptation of the invention any number of chains, in the present instance two pairs of substantially parallel and spaced apart continuous chains, one of which pairs is adapted to run continuously when the device as an entirety is in operation and is designated as continuous feed conveyor 1 and the second pair of which may run intermittently or continuously, ldependent upon the proper feeding of4 boxes by .both said feed conveyors, and designated as intermittent feed conveyor 8. The conveyor 8 has spaced apart substantially parallel chains 9 and Y I0 passed over sprockets II and I2, the sprockets floor.

being mounted upon a shaft I3, the shaft being carried injournals secured to angle type, substantially parallel and spaced-apart guide frame members I4 and I5, which may rest upon the These guide frame members are braced and held in substantial parallelism in any suitable manner, such as by cross brace pieces, of which there may be a plurality and here designated as I6.

Secured to the shaft I3 is a clutch Il. The clutch is in two parts I8 and I9. The part I8 constitutes a drum having secured thereto a sprocket 20. This sprocket is adapted to be driven, as hereinafter described. Within the drum is a split brake shoe 2|. A cross piece 22 is secured to the shaft I3 and to the brake shoe, to the end that when the brake shoe is in engagement with the inner surface of the drum i,other desired location.

, spring is interposed between a collar 26, forming a part of the member I9, and a stop washer 21 secured to the end of the shaft I3. When the spring 25 is compressed, as shown in Figure 2, the brake shoe is out of engagement with the inner surface of the drum, with the result that the shaft I3 is not rotated, irrespective of rotation of the drum I6. No inventionis claimed in l this clutch, per se, as it is, of an ordinary type readily purchasable upon the market. l

'Ihe upper reaches or lengths of the feeding conveyor chains 9 and `Iii are preferably received in channel members 28 and 29,v which act 'as supports for the chains while the chains are carrying a load. The length of the chains is immaterial and will, of course, depend upon the number of 'boxes adapted to be loaded thereon for movement toward the stacking mechanism.

The continuously runningfeed conveyor includes, in the present instance, apair of spaced apart chains-3ll` and 3i, the chain 38 being in substantial alignment with the chain 9, and the chain 3I in alignment with the chain I8. An

idler shaft 32, received in suitable journals beneath the guide frame members I4 and I5 carries thereon sprockets 33 and 34, over whichthe chains are trained. A drivei shaft 35 for the chains and 3i is suitably journaled beneath the frames `I4 and I5, the shaft carrying thereon sprockets 36 and 31, over which said'chains 30 an`d 3l are trained. One end of the shaft 35 carries a sprocket 38', this sprocket having a continuous chain 39 trained thereabout, the said I chain in turn being trained about a second sprocket 40 secured on a shaft of a suitable reduction gear, not illustrated, the gear in turn' being driven by a motor 4I. This drive mechanlsm is illustrated in Figure 4 as above the oor line, and for clarityof the views, the motor and chain are not shown in the remaining drawings. As is obvious, the motor may be placed at any The upper reaches of the chains 30 and 3| are adapted to be guided as to movement and likewise held within guide zones adjacent the sprocket wheels 33 and 34 are rockably mounted by providing lugs 44 for each guide channel beneath the same and carried upon a cross bar 45, the bar being secured between the guide frames i4 and. I5. A pair of cross braces 46 and 41 are interposed between the guide channels and-secured to the cross` brace 41 is a depending lug'48, the lug in turn having rockably secured thereto a link 6 9. Rockably secured to the link and at one end thereof is a lever 56.- This lever is secured to a boss 5I carriedon the shaft 35 between the sprockets 36 and 31 (see-Figure 1). This lever is of extended length and is adapted to be rocked relative to the shaft 35, dependent upon movement of an elevator for the stacking of the boxes, and as hereinafter more fully detailed. For the present, `it

may be said that the lever when rocked, will raise and/or lower the channel members 42 and 43, for instance to the position shown in Figure 5,

. when the clutch is disengaged, it is evident thatv or to the position shown in Figure 6. It is intended that the chain conveyors 38 and 3| should bey trained loosely about the sprockets so that the upper reach of said chains may assume the position shown in Figure 5, or the position shown in Figure 6. It is obvious that this would occur for 'the reason that the. ends of the channel guides adjacent the idler sprockets are rocked about cross bar 45 by the movement of the link 49.

Interposed between guide channels 42 and 43 and'the guide frame members I4 and I5 are means designated generally as 52, the said means constituting a plurality of, rollers 53, suitably carried in frames 54. These frames are held by 'brackets 55 to the guide frames I4l and Il.

When the upper reach of each chain is in the position shown ln Figure 5, each chain is spaced slightly aboveV the periphery of the rollers, but when the link 49 lhas been' actuatedth'rough movement of the lever 50, the upper reach of each chain is below the periphery of the rollers. as shown in Figure 6.

'I'he shaft 35 carries a sprocket at 56, and a continuous chain is trained between `vthis sprocket and the sprocket 28 secured to the drum I8. `As before stated, when the shaft 35 is being driven, it is evident that the chains38 and 3l will be continuously moved and that if the clutch is engaged, that the chains s and Iii will likewise be continuously moved. The intermittent movement of the chains 9 and I8 will depend upon operation of the clutch through mechanism .which constitutes a pair of bell cranks 51 and 58, fulcrumed to brackets 59 and 68, the brackets in'turn being secured to the guide frame mem` 'ber l5.

'The'other levers 63 and 84 of the bell cranks are secured to links and 66, the links in turn being secured to ends of a lever 81. The lever 61 is intermediately rockably trunnioned to the collar 26. When the levers 51 and 58 are moved to the full line position of Figure 2, the lever 61 is in the position shown inl Figure 2, and the clutch is disengaged. The lever 58 may assume the position shown in Figure Al, with the lever 51 in the full line position, or the lever 58 may assume the dotted line position at 68, thelever 51 being in the full line position of Figure'2 and the clutch will remain engaged. In other words, until both levers are in the full line position of Figure 2, the4 clutch is at all times engaged. However,

the conveyor chains 9 and I6 will not be moved, whereas the conveyor chains 30 and 3i will be continuously moved. k

As hereinafter more fully detailed, the exact position for mounting the bell cranks will depend upon. the length of the boxes to be moved by said conveyor chains.v Thus, in the showing of Figure 2, we have two boxes, 69 and 10. As long as the boxes are Vproperly spaced and the elevator mechanisrmto be described, isnot in operation, the conveyor chains will move continuously. However, if the elevator mechanism is in operation, the lever 50 will be rocked upwardly for o'ne end and downwardly where the link/49 connects 52. When this occurs, it is necessary that thebox 10 not continue onto the/chains 38 and braces, as hereinafter set forth. The frame up- 3|, which conveyor chains are, of course, continuously moving. Hence,the bell crank 58 is so positioned that the lever 62 will be rocked to .the position shown in Figure 2 by engaging the side ofthe box 69. As the box 10 is following, upon engagement with the lever 6|, said lever will be moved from the position of Figure 1 to that shown in full lines in Figure 2, and in so doing, will disengage the clutch, whereupon the conveyor chains 9 and I0 will cease movement, the box will now remain in the position shown in Figure 2 until the elevator has assumed correct position for receiving the box 69, whereuponv the lever 50 will be rocked to move the link 49 and raise the channel guides in the upper reaches of the conveyor chains 30 and 3| above the peripheries of the rollers 52, atv which time the box will move onto the elevator.' When the lever 62 escapesfrom the rear edge of the box, the bell crank will rotate and the clutch will again engage, which will reestablish movement of the conveyor chains 9 and 0, to thereby move the box 10 onto the continuously operating conveyor chains 30 and 3|.

The guide frame members I4 and |5 are secured to a framing structure, designated as an entirety by 1|. This framing structure includes side uprights 12, 1,3, 14'and 15. Secured between the side uprights are base framing members, designated generally as 16, and upper transverse bracing members 11 and 18, respectively, *extend-` ing between the uprights 12 and 14, and uprights 13 and 15. Otherbracing members are provided intermediate the topI and` bottom transverse rights extend above and below the floor line 5, as shown in the figures.' l

The elevator 4 is so carried by the framing as to lie in the path of the feeding conveyor so as to receive and have boxes deposited thereon, and likewise to raise the said boxes within the stacking trough 6, the elevator to this end being vdisposed to be received within said stacking'trough.

The elevator 4 includes-a base 19 reenforced by plates 80 and 8|, and side members 82 and 83, with spaced-apart rollers 84",- interposed between said side members. The rollers are transverse to the path of movement of the feeding conveyor vchains 30 and 3| so that a box may be readily received upon the elevator. However. one of the rollers. has a braking device 85, which tends to restrict .rotation thereof. 'Ihis braking device includes an arm carrying a brake shoe bearing against the periphery of the roller, and the roller selected in the present instance is the one adjacent the last roller, that is to say, a roller removedfrom the feeding conveyor. It is intended that movement of the box upon the conveyor while free to move upon the first two rollers.' nevertheless is restricted as to movement by the next roller so as to retard movement of the boxas it finally positions itself upon the elevator.

Secured to the base 19 is an elongated tube 86 passed through a guide sleeve 81 positioned adjacent the base of theelevator when the elevat-,or is inl its lowermost position. This guide sleeve is suitably held in position by spaced pairs of transverse bracing members 88, 89, 90 and 9|, secured by means of angle pieces to front and rear .pairs of transverse brace members 92, 93, 94 and 95 (see Figure '7). The brace members 92 and 94 are heldto the `uprights 12 and 13 in any suitable manner, and the .brace members 93 and 95 are secured to the uprights 14 and 15. The lowermost end of the tube 86 has secured 18 thereto a collar 96 provided with a pair of diametrically disposed arms 91 and 98, the ends of which carry rollers 99 and |00. These rollers are adapted to ride upon rails |0| and |02. The rails are secured in substantial parallelism at their upper ends to the members 94 and 95, and at their lower ends to certain members of the base framing 16, to wit, the members |03 and |04. When the tube of the elevator is adapted to be moved by suitable means which is secured to the collar, any tendency of the tube to bind within the guide sleeve 81 is prevented by the roller contact with the rails. Thus, easy operation of the tube is assured.

' To raise and lower the elevator 4, I have provided means designated as |05. This means includes a motor |06, which through the medium of a reduction gear |01, is adapted to drive a large gear wheel |08. This gear wheel has secured thereto one end of a chain |09, the opposite end of the chain being secured to a lug ||0 formed on the collar 96. The motor |06 may be secured by a suitable mounting attached to the base framing 16. This motor has its shaft 5 driving reduction gearing within a housing ||2,

chain |09 carries a swiveled bolt ||6, the bolt being secured to a stud ||1 journaled on a trunnion ||8, this trunnion H8 being carried upon a slide I9 received in t groove |20 of one of the spokes of the gear. The slide ||9 is provided with a pair of elongated slots, and bolts |2| and |22 (Fig. 5) pass through the slots and through openings in the spoke of the gear, whereby the slide may be adjusted radially of the gear spoke. 'I'he gear |08 carries an arcuate strap |23. A switch, designated as an entirety by |24, is adapted to 4be actuated -to open the same when vcontacting the arcuate strap. Said switch includes a housing |25, and a rotatable wheel |26 secured on the end of a switch arm in such a manner that when the wheel is engaging the arcuate strap, the arm is moved to open -the switch, and when the wheel is out of strap engagement to allow the switch arm to close an electrical circuit. The housing is carried on a .bracket |21 secured to the framing upright 13a. It is to be noted that when the elevator is in its lowest position, as shown in Figure 5, that the roller -|26 of the svgtch is in engagementwith the arcuate strap Substantially paralleling the tube 86 is means |28 for arresting downward movementl of the elevator. This means includes a cylinder |29, the base of which is secured to a transverse framing member |30. Within the cylinder is a lpiston |3|. The piston arm |3i is, by means of a fitting |32, secured to the plate 8| of the elevator. Secured adjacent the base of the cylinder is an air inlet valve |33 and -a'n airoutlet valve |34 (see Figure 8). The air inletvalve includes a cap |35 in threaded engagement with a. nipple |36, the cap beingl formed `with an opening |31 with a spring-pressed ball, designated generally as |38, normally seated within the opening |31 and closing the same. The arrangement is such that when the elevator moves upwardly to move` asiaeve is provided with e threaded nipple it having connected thereto the valve lait. The plug Mt Aor the valve has tivo bores isi and M2 of dierent diameters. The bore lili of the nlug is substantially uniiom with the diameter oi the bore in the valve i3d. 'mien the plug is turnedy clit angles, the bore M2 is so positioned that air from the cylinder must escape through the smell filmster bore or the pluri The rate oi escape o oir from the cylinder determines rate or des-cent oi the elevator. Until the lest foon or a selected timber or boxes for a stack. has been received the stacking trough e, the plus is not rotated to position the bore M2 in alignment with the bore oi the valve bod?. iii-oineans for rotating,` the plus will be hereinait The sta trough is adapted to be so positionecl "e to the elevator that the elevator is centr creer, to the end that a box to be raised evator withinthe stacking trough be c .d by said troh, and. thereby be prevented nom dislodsment or movement during .s stac operation of the boxes. The stacking i a rear or basis Wall i513, and two ed apart in substantial'parallelism with the 'rear wall. These side at ide and iet. The construc- *lnat the side Walls ist and ist are of than the rear wall lili-i, and the rear .nds downwardly and rearwardly of es seen in Figure 7, wherein it will be ci -l at rear wen is sangen at ici with e tr nsverse strap Mit secured to the external s irroce o said Wall in any suitable manner, by means tif" and which strap iitl is provided with end braciand i5 i, the brackets in turn being secured :by means ide and tt to the framing members and i3 (see Figure e). Thus, the 'socle member or the trough is rigidly held in p0- stion to t e framing. The sides ib and me have secured t"-ereto elongated angle brackets i555, 55 and i515 (see Figures 3 and 5). The angle brackets in turn are secured to the transverse bracing mem rs il and i3 in any appropriate manner, such as by the bolt-nut arrangement shown (see Figure 5). "in Figure 7, it will be observed that the angle bracket 55 is secured between the ransverse frame members il and lil. Brace members li and tot are secured to the sides, for the purpose of giving rigidity to the stacking trough. The sides U and MS of the stacking trough are relatively divergently bent to provide Wings it and itil. These wings act as guides to assure proper entrance of the boxes Within the stacking trough. For instance, if a box is not completely centered upon the elevator and the elevator is raised, one or the other of the guide wings will Contact an edge of the box and force the box to center within the confines of the stackine trough.

I have provided means adapted to maintain a. lowermost box of a stack, or a single box, at a selected distance above the elevator when the elevator is in its lowermost position. with the said box or boxes connned by the three walls of the stacking trough. In particular, the said means includes members adapted to be actuated by the work to move the same from the path of movement of a box resting upon the elevator during upward movement thereof to permit said box to pass beyond the confines of said means, and

thereafter to move beneath 'said Wort; to engage the worlr as the elevator adorn descends to its initial bon receiving position. This seid menos' is arranged to cooperate with other mechanism which actuates said means when the last box to be stacked has been raised to a position by the elevator to brins said box into worte engagement with the remainder oi the stacked bones. it that time, the said means is held open during descent of the elevator with the stacked boxes thereon; The said moeras includes a pair oi members @Gi and it, each member including a pair oi arms it@ and ist (eee .Figure 7), a portion or the arms beine bentes chown at itt, with e shoe de@ en tending between ends oi the bent portion oi each pair oi arms, the shoe beine provided ewith a dat supporting toto` iol and o pair oi dans@ portions it@ and tot), the :danse portion it@ overlying the parallel pair or arme, the opposite end portions ci each pair or arms being provided with luso ille, the lugs iseved or otherwise secured on a shaft il i, the strait ci which is carried in lowing blocks V12 and it, secured to the frame uprishts tl and le, respectively. The other pair oi arms is secured in the same manner to the trame up= rights H2 and lil isee Figures Si and el. Tous, the pair or crine is rociracly mounted so as to stains intverdly or the stacking trough, which is to say that the shoe members moy approach each', other or sis-ving apart. Normally, the shoe ends or the armsare urged in one direction, that is, ine wordlv or the steering trough. However, thesis grec of inv/'ard movement is controlled by notched, recessed or cutout portions il@ il@ in the basis wall or the stacking trough. These cuteout portions are adapted to receive the shoe portions oi the arms (see Figures to d, inclusive); The arms are urged into the cut-out portions illl end or the bolt secures the bracket, the bolt and the spring inl position. The spring is of the compression type, and hence urges the, arm itl to swing about its pivot point so that the shoe is normally received within the cut=out portion il@ oi the back wall oi the trough. v

in order to stop movement of the box which is directed onto the elevator when the elevator is in its lowermost position, a stop plate iii is provided. This stop plate is secured by means oi upper and lower brackets to the member iti and speciiically to the parallel arm members itil and iet thereof. Figure 6 illustrates movement.

, that may occur when the member iti is rocked about its shaft il l. A switch db2 includes a casing secured to the' plate tot, a. switch actuating portion comprising e; wheel IIt projecting through a slot in the' plate iii, as shown at ist in Figures l, 5 and 6. Movement or tins wheel in one direction will close the switch contacts 'isb (see Figure 9). The wheel is normally urged in one direction, to wit, forwardly of the front face or box engaging face of the plate through the medium of a coil spring |86 (see Figure 9). The arrangement is such that when a. box is received upon the elevator, the elevator being in the position oi Figure 5, the switch wheell will be moved to close the contacts |85, which will complete an electrical circuitthrough an iron core coil |81 and attract an amature |88 brace l|4|9 and likewisethrough avr further guide of a switch to move two contact arms |89 and |90 into engagement with contact points I9| and the arcuate strap |23, completes an electrical circuit through contact |96. The arrangement is such that contacts |85 remain closed while the roller |26 is riding upon the arcuate strap, and at or after the roller |26 escapes from the arcuate strap to close contactbetween the arm |95 and the contact point |96,the contacts |85 will open. This arrangement maintains the magnetic switch. |81 in operation so that the motor |06 continues to operate until the roller |26 again engages the arcuate strap |23 and opens the switch |24, thus stopping operation of the motor by breaking the current path.

I have provided means whereby when number of boxes have been stacked on'e upon the other and received within the stacking trough at a selected elevation therein, that upon the further addition of a bo x to said stack, certain means will be actuated to move the members I6I and |62 out of box engaging position and at the same time bring into operative position the discharge conveyor ,3, so that when the elevator with the stacked boxes thereon is lowered, the discharge conveyor will remove said stack of boxes to any given location, as selected. This means for moving the members I6| and |62 out of box engaging position and for actuating the discharge conveyor, is designated as an entirety by |91.

Means |91 includes two rods |98 and |99 joined together by a coupling 200, the said coupling iny cludng a tube 20| threadedly secured by means 202 to the threaded end of the rod |98 while the rod |99 is received within the member 20| and carries a head 203, between which head and end 204 of'tube 20| and surrounding the said rod |99, is a coil spring 205. The back or rear wall |44 of the stacking trough is provided with a centrally disposed longitudinal slot 206. Adapted to project through said slot is an arm 201 formed at one end with a iitting 208 `whereby it may be adjustably secured on the rod 99. That portion of the arm which is received within the stacking trough carries an angle member A209, and this angle member is substantially atright angles to the length of the rod |99 and in such a position as to be in the path of any box received within the stacking trough, when the box stackl reaches a predetermined height Within said trough. 'I'his angle member may be held to the arm in any approved manner, such as by the nut arrangement shown at 2|0.

The rod |98 passes through a guide tting 2I| secured to the member I 55 and said rod |93 above said fitting 2|| is provided with an adjustable collar 2|2, which acts as a stop means upon engagement with the fitting 2| I to limit downward movement of the rod |98. The rod I 96 is passed through `a. further guide fitting 2|3 secured to brace member 94. The rod |98 is provided with collars 2|4, 2|5 and 2| 6, adjustably secured thereon. As shown in Figure 4, the `rod |99 is passed through a guide fitting 2|1 secured lto a given fitting 2 |8 secured to transverse bracing member 2|9 at the top of the rear wall of the stacking trough. Further bracing members for the upper end of the trough are shown at 220 and 22| (see Figure 1). VThe collar 2|4 is provided with a stud 222, and a pair of links 223 and 224 have ends thereof journaled on said stud, with the opposite ends ofv both said 'links provided with elongated slots 225and 226. Bolt members 221 'and 228v secured to the members |6| and |62 are passed through said elongated slots 225 and 226 s o that certain actuation of the links will produce movement of the membersv |6| and |62. The

links are provided withdepending arms 229 and v V230 and a coil spring 23| is secured to the outer i ends of said arms. The arrangement Iis such that s to swing a given degree about pivot points withtoggle isin this position, the spring 23| and out causing appreciable movement of said links. In order to check downward movement of 7the member |91, considered as an entirety, I have ,provided the means shown at 232 comprising a cylinder 233 rockably secured at one end by means 234 to member 94. A piston is within saidv cylinder and a piston stem 235 is secured to the collarY 2|5. The usual air' outlet, not shown, is

^ provided for this particular cylinder so that air maybe allowed to enter the cylinder behind the piston as the piston rises,` and likewise to slowly escape therefrom so that any dropping eiiect of the member |91. as an entirety is cushioned.y

When the toggle is in the 11n-made position as shown in Fig. 4, the pivot 222 is below the center of links 223 and 224l and the spring 23| pulling on arms 229 and 230 tends to force the arms |6| A tothe coupling arrangement 200 and cause the 4 links to pass center and be held past center by the spring 23|, or in the dotted position shown in Figure 6 at 236. This forms a true toggle and when the parts are moved to .this position, it is evident that said links will forcibly separate `the I members |6| and |62, as shown in Figure 6, and hold the said member separated.` When the springs |16 tend to force the arms IBI. and |62 toward each other. The weight ofrods |98 and |99 and angle member 209 is insufficient to overcome this tendency and the toggle is thus held in made. position until released by means to be presently described. Furthermore, the piston within the cylinder 233 will be raised so as to provide a-pneumatic cushion when the rods |98 and |99 again move downwardly. The collar 2|6 is forcibly moved upwardly during the stacking of the last box within the trough and this movement is such as to actuate certain members to be presently described, to bring into operative position the discharge conveyor 3, to the end that the stack of boxes, when lowered by the elevator, will rest upon the said conveyor and be moved a sprocket 295 is secured to the drive shaft 35 (see Figure 1) Thus, when the box has been fed a certain distance by the continuously running chains of the feed conveyor, the box will contact the periphery f the rotating feed roller 289 and be moved onto the elevator.

Depending from that portion of the elevator which faces the oncoming box fromv the feed conveyor is a box stop member 296. This box stop member is in the form of a rectangular framing. The upper end of the framing is flanged and by suitable means, such as nuts and bolts 291,

the iiange is secured to the base 19 of the elevator. Thus, when the elevator moves from the position of Figure 5 to that of Figure 6, the stop member 296 blocks entrance so that an oncoming box may not enter beneath the elevator. A further stop means is provided in the form of a stop bar 298, forwardly of and adjacent the periphery of the feed roller 2119,y Thus, when the continuously running feed conveyor chains are inthe position shown in Figure 6, any box moving toward the feed roller, will be stopped from contact therewith by the stop bar. This stop bar extends between the upright framing members 12 and 14. v A

For the purpose of guiding the boxes as they are delivered from the continuously running feed conveyor onto the elevator when the elevator is The lever 50 which controls elevation of thev channel guides for ythe upper reaches of the continuously running chains of the feed conveyor, is limited as to' its swing through the medium of tie bolts 303 passed through openings in the framing member 231. Through the medium oi' nuts 304, adjustability in movement of the lever4 is eected.'

In Figures l and 2, I have'illustrated clutch mechanism I1 adapted to be actuated in such a manner as to control movement of the feed' rangement designated generally as 406. This arrangement comprises a bar 409 fastened to the link 401 and overlapping the portion 406. The arm 405 considered as an entirety is channel in cross section andextending through the top arm is urgec1 to rotate clockwise, viewing Figure 11, although the rotative movement is restrained. As the remaining portions of the device illus- `trated in Figures 10 and 11 correspond to Figures 1 and 2, the mechanism will not be further described. Y

Referringto Figures 12 and 13, I have illustrated a modification of certain of the means s I05 .to raise and lower the elevator 4. A gear 4I1 stant radius from the zone 43| to 432.

conveyors, to the end that loaded boxes are l .prevented from being fed to the elevator if the elevator is raised during a box stacking operation, or if the elevator is lowered for they purpose of discharging the stacked boxes.

Referring to Figures 10 and 11, the feed con-.

has one of its spokes 4I8 transversely bored to permit passage therethrough of a shaft 4 I 9. One end. of the shaft has pinned thereto an arm 420. This arm carries a trunnion42 I, and upon which trunnion is secured a stud 422. This stud is adapted to receive the bolt H6, which is secured by suitable means tothe end II5 of chain |09. 'I'he shaft 4I9 has pinned thereto an arm 423. The arm carries transversely at its outer end a roller 424. Secured to the side upright 13 is a block 425, which block has la bearing portion 426. A shaft v421 is passed through said bearing portion and the gear wheel 4I1 is keyed thereto at Surrounding the part 426, and fastened thereto so as not to move is a cam 429.- This cam is provided with a facial groove 430 `adapted to receive the roller 424. As illustrated in Figure 12, the cam groove has a substantially con- From 432 to the zone 433, the radius gradually increases. and .from 433 to the zone-43I, the cam' groove is -substantially straight. The operation, uses and advantages of the inanisms have been on the market, but so far as at 402 in Figure 11. The shaft 45 carries a link g at present known, most of said devices are quite expensive to construct and require supervision as to maintenance. The'present invention contemplates a feed conveyor and a discharge conveyor both leading to a stacking mechanism which includes an elevator adapted to raise the boxes to stack the same within a stacking trough.y Primarily, the feedv conveyor is in two parts, one of which parts continuously operates and the other mayoperate either continuously or intermittently, dependent upon a proper feeding of the boxes to the elevator.- If boxes are placed upon the feed conveyor, said boxes, if improperly spaced when brought in juxtaposition to the elevating mechanism, will be. prevented from attempted placement upon, the elevator through mechanism which while not stopping operation of the continuously operating feed'conveyor, nevertheless moves said conveyor out of box engagebox will contact the same to move the switch arm ment. 'I'his condition will occur when the elevator is in the act of either raising a box withinthe stacking trough or while the elevator is being lowered. When the elevator is in position to receive a box, certain mechanism is operated which raises the continuously operating feed conveyor to move said box onto the elevator, and operation of the second member of said feed conveyor is resumed through the medium of a simple clutch arrangement, which may be thrown-out or thrown-in in accordance with the spacing of the boxes upon the feed conveyors, and the operation of the elevator. Hence, so far as this portion of the mechanism is concerned, the device is capable of functioning continuously without supervision to properly space the boxes upon the feeding conveyors so that boxes may be properly received upon the elevator. A simple expedient in the form of arms is pro vided for supporting the stacked boxes within the stacking trough, and lwhich arms function to spread apart as a box is elevated by the elevator', and then to swingunder the lowermost box to hold the stack of boxes in position within the .stacking trough, while the elevator again descends to receive a further box. When the last box to be received within the stack is raised by the elevator, the uppermost box will strike the cross arm 209 and raise the rods |99, which in turn will move the links 223 and 224 and actuate the arms |6| and |62 to cause relative separation thereof and allow the entire stack of boxes to descend as the elevator descends. This action likewise brings' into operation the discharge conveyor which will remove the stack of boxes to a selected location, in say, the warehouse. When the stack of boxes has been moved A from the elevator by the discharge conveyor, contact is made with part 211 of lever 216 permitting a drop of the upper reach of the discharge conveyor chains. When this occurs, the upper reach of Asaid chains will be below the top surface of the rollers of the elevator.

The operation of the modied forms of certain offthe mechanism of the invention as i1- lustrated in Figures 10 to 13, inclusive, is undoubtedly obvious. However, it may be pointed out that as to the mechanism depicted in Figures l0 and 11, the' clutch mechanism shown in Figures l and 2 is dispensed with. As the boxes are carried on the conveyor chains 400 and toward the elevator, there will come a time when movement of the chains must be stopped due to elevator position. Ordinarily, the mechanism will be as shown in Figure 11, but if the elevator lis raised or boxes are being discharged when the elevator is'in its lowered position, the chains 400 and 40| must `be lowered so that the boxes will not move forwardly. To accomplish this,

Ythe switch arm 4|5 is adapted to be actuated so as to break the electrical circuit leading to the motor which, through the medium of a continuous chain, turns the sprocket 38. The lever 50 maintains the guide channels in the position shown in Figure 1l when the elevator is in its lowered position. -When the elevator is raised, the lever 50 allows the channels to drop thereby lowering the chains 400 and 40| below the rollers 53, or to the position illustrated in Figure 6.

When the elevator is in its lowered position, and the discharge conveyor system is ready tooperate, the arm 405 will be moved upwardly, thereby positioning the wheel 4|6 above the upper surface of the conveyor chain so that anon-coming and break the circuit to the "motor adapted to drive the conveyor chains. To assure against breakage of the arm 405, in the event the switch arm is actuated to the excursion of its movement, I have provided the overload spring arrangement 408, previously described. I

'Ihe form of the invention shown in Figures 12 and 13 is useful in that the elevator is moved at a slow rate of speed until a box is brought into contact with a box resting upon the supporting tops |61 of the arms IBI and |62. This is accomplished through the provision of the cam 429, which controls the actuation of the elevator through the medium of the chain |09. Taking the position of the cam as shown in Figure l2, rotation of the gearl is anti-clockwise, or in the direction of the arrow. The full line position shows the roller 424 in the position that it would assume relative to the facial groove of the cam vwhen the elevator is in its lowermost position as, for instance, illustrated in Figure 5. Likewise, as illustrated in Figure 5, a boxvshown in dotted lines is resting upon the elevator. There is a slight distance that the elevator must move to bring the box into engagement with the shoes carried by the bent arms |65. As before stated in detail, it is intended that a box being raised by the elevator should not permit the shoes to be totally disengaged from beneath the lowermost-box, or a. stack, until the box being raised is almost in contact with the stack.

box ofl the stack. This is accomplished by the cam and particularly the straight portion of the cam, being that portion between the full line position and the dotted line position for the roller 424. After the box being elevated has contacted the lowermost box of the stack, the speed of raising of the elevator is accelerated by the construction of the cam, until a time is reached when the elevator must again descend. The lelevator descends at a uniform rate of speed.

Various refinements have been incorporated in the present mechanism, such as pneumatic -means for controlling the rate of movement of the elevator as it moves downwardly either with or without load, as well as pneumatic means for .the elevator to descend and upon reaching a given level, stop motor operation without any further travel of the gear |08.

It is thought that the dual switching arrangement is novel. Other novel features are thought to reside in the two-part feed conveyor, with means controlled in part by movement of the elevator, to bring the'upper reaches of one of the feed conveyors into box engagement or out of box engagement. The discharge conveyor provides a new arrangement. y

I claim: i

l. The combination in box stacking and conveying mechanism, of a stacking trough, an elevator adapted to sequentially raise boxes within said trough to form a stack, a pair of spaced, movable, support members engaging the lowermost box of the stack elevated within the trough during each ascension and descension of the elevator, a shiftable member mounted adjacent to one side of the trough and a pair of toggle arms secured to the shiftable member and to the pair of movable support members and operable by the uppermost box after a selected box stack height has been reached for releasing the support members from the lowermost box of, the stack to permit descent thereof on said elevator. s

2. In a device of the character disclosed, a stacking trough to receive boxes, a pair of swing arms provided with supports positioned ony opposite sides of the stacking trough and receivablel in part within the trough, anvelevator adapted to receive a box and to move said box upwardly within the trough and past said arms, the said" arms swinging apart to permit passage of the box within the trough followed by swinging beneath the box to prevent descent thereof, a cross arm within the trough, a rod secured to said arm, and a pair of toggle arms secured to the rod and to the swing arms, whereby after a given number of aboxes have been stacked within the trough, the cross arm is moved upwardly by the uppermost box oi' thestack to move the rod and the toggle arms to swing the arms apart and release rthe stack of boxes.

3. The combination-in box stacking and conveying mechanism, of anl elevator, a stacking trough within which said elevator is adapted to raise boxes, a feed conveyor for conveying boxes onto said elevator, means for raising said ele--v vator and said boxes within the stacking trough when received on said elevator, a pair of spaced movable support members adapted. to engage beneath the raised boxes tol hold the boxes elevated within the trough,l the elevator descending; a shlftable member mounted adjacent to one side of the trough and a pair of toggle arms secured to the shiftable member and vto the pair of movable support members and operable upon the stackingy of a selected number of boxes within said trough to cause said toggle arms to release the support members and permit the stack to descend as the-elevator ,is lowered, and a discharge conveyor adapted to move the stack from said elevator and outwardly of said itrough.

4. The combination in box stacking and conveying mechanism, of an elevator having a box supporting surface, a stacking trough, means for raising and lowering theelevator within s aid stacking trough, a feedconveyor for feeding a box onto said elevator to be raised by said elevator within the trough, swing arms adapted to be separatedupon elevation of the box and movable inwardly beneath the box to hold the box within the stacking trough, the elevator descending, a discharge conveyor, and means actuated upon a certain number of boxes being stacked within said trough to position said discharge conveyor above the supporting surface of said elevator when the elevator is in its lowered position, the said elevator depositing said stack of boxes on said discharge conveyor.

5. The combination in box stacking and conveying mechanism, of an elevator having a box supporting surface, a stacking trough,means for raising and lowering the elevator within said stacking trough, a feed conveyor for feeding a box onto said elevator to be raised by said elevator within the trough, swing arms adapted to be separated upon elevation of the box and movable inwardly beneath the box tohold the box within the stacking trough, the elevator descending,.a discharge conveyor, means actuated upon the stack has been conveyed a selected distance from the elevator.

6. In a abox handling apparatus, an elevator, means to raise and lower said elevator, a stacking trough positionedin the path of movement of the elevator, means in the path of movement of a. box in the trough to support a box in said trough upon delivery thereto by said elevator, means to convey boxes to the elevator, a discharge conveyor extending into the path of movement of a stack of boxes in the trough, said .discharge conveyor being movably mounted and being normally out' of engagement with a box on the elevator when the lattter is in lowered position and means to shift said discharge conveyor to position to be engaged by a box lowered by the elevator.

'7. In a box handling apparatus, an elevator.' means to raise and lower said elevator, a stacking trough positioned in the pathof movement of the elevator, means in the path of movement of a box in the trough to support a box in said trough upon delivery thereto by said elevator,

means to convey boxes to the elevator, a discharge conveyor extending into the path of movement of a stack of 'boxes in the trough, said discharge conveyor being movably mounted and being normally out of engagement with a box on the elevator when the latter is in lowered position, means to 'shift said discharge conveyor Y to position to be engaged by a box lowered by the elevator, and means to cause a stack of boxes in the elevator `to be lowered when the .stack reaches a predetermined height.

' 8. In a box handling apparatus, an elevator, means to raise and lower said elevator, a stacking trough positioned in the path of movement of the elevator, means in the path of movement of a-box in the trough to support a box in said trough upon delivery thereto by said elevator, means to convey boxes to the elevator, a discharge conveyor extending into the path of movement of a stack of boxes in the trough, said discharge conveyor being movably mounted and' being normally out of engagement with a box on the elevator `when the la'tter is in lowered position, means to shift said discharge conveyor to position to be engaged by a box lowered by the elevator and` means to simultaneously cause the stack to be lowered and said discharge conveyor to be moved to stack engaging position.

9. In abox handling apparatus, an elevator having a supporting surface,A means to raise and lower said elevator, means to'stack boxes above the, elevator upon delivery by said elevator,

'means to lower a stack of boxes when said stack becomes of a predetermined height, and a discharge conveyor, said discharge conveyor being normally below the supporting surface of the elevator when the elevator is in its lowered position and means to move the discharge conveyor to a position above the supporting surface of the elevator when the. latter is in its lowered position, said discharge conveyor being adapted to remove the lowered stack from said elevator..

10. In abox handling apparatus, an elevator having a box supporting surface, a feed conveyor tion and means to move the discharge conveyor to a position above the. box supporting surface of the elevator when the latter is in its lowered position, said discharge conveyor being adapted to remove the lowered stack from said elevator.

11. In a box handling apparatus, an elevator having a platform thereon, a delivery conveyor adapted to deliver boxes upon said platform, means to raise and lower said elevator, means above the elevator to support boxes upon delivery thereto by said elevator, means to release said support means to thereby cause said elevator to lower a stack of boxes when said stack becomes of a predetermined height, and a discharge conveyor chain at each side of said platform and in the path of a lowered stack of boxes, said chains being adapted to discharge a stack lowered by said elevator.

12. In a box stacking apparatus, an elevator, means to raise and lower the elevator, a box support on the elevator, box guiding means in which the elevator moxes, said guiding means having a width greater than the width of the box supporting means whereby a space is provided at each side of the support, a conveyor chain mounted in each space, means to mount said conveyor chains for movement from a position above the supporting surface when the elevator is in the lowered position to a position below the supporting surface when the elevator is in its lowered position, means to raise and lower the conveyor chains and means to drive the conveyor chains.

13. In a box handling apparatus, an elevator having a platform thereon, a delivery conveyor adapted to deliver boxes upon said platform, said platform including a plurality of rollers having their axes extending transversely of theA path of movement of a box delivered to said platform, means actuated by the delivery of a box upon said platform to raise and lower said elevator, means to support boxes upon delivery thereto by said elevator, means to release said support means to there'b-y cause said elevator to lower a stack of boxes when said stack becomes of a predetermined height, and a discharge conveyor chain at each side of said platform and adapted to engage the lowermost box in a stack and to discharge the stack lowered by the elevator.

14. In a box handling apparatus, an elevator having a platform thereon, means to raise and lower said elevator, a discharge conveyor including a pair of substantially parallel continuous chains, a portion of said chains being adjacent opposed sides of said elevator platform, the top most part of said chains adjacent said elevator platform being normally below the level vof the raise said chains adjacent said elevator platform above the level of the top of said platform when the platform is in its lowered position upon the lowering of a stack of boxes in said trough, whereby said chains will engage'sald stack when said elevator is lowered and Will remove said stack from said elevator platform, and means to lower said chains adjacent said elevator platform to their normal position upon the discharge of a stack of boxes from said elevator platform.

15. In a box handling apparatus, an elevator` having a platform thereon, means to raise and lower said elevator, a delivery conveyor adapted to deliver boxes to said elevator platform, a stacking trough parallel to the path-of movement of said elevator, means to support a box in said trough upon delivery thereto by said elevator, means to release said support means to cause said elevator to lower a stack of boxes in said trough when said stack becomes of a predetermined height, a discharge conveyor including a pair of substantially parallel continuous chains, a portion of said chains being adjacent opposed sides of said elevator platform, the top most part of said chains adjacent said elevator platform being normally below the level of the top of said elevator platform when the -elevator platform is in its lowered position, means to raise said chains adjacent said elevator platform above the level of the top of said platform when the platform is in its lowered position upon the lowering of a stack of boxes in said trough whereby said chains will engage said stack when said elevator is lowered and will remove said stack from said elevator platform, and means to lower said chains to their normal position upon the discharge 0f a stack of boxes'from said elevator platform.

16. In a box stacking apparatus, an elevator,

- box guiding means above the elevator, a pair of pivoted arms disposed upon opposed sides of the guiding means and movable into a position beneath a box in the guiding means, means to raise the elevator, means normally urging the arms towards each other into box engaging position, pivoted link means for holding said arms separated, a rod for actuating said link means and means operated by a box in said guiding means for moving said rod and liinks to cause said arms to move from box engaging position.

17. In a box handling apparatus, an elevator, a delivery conveyorv adapted to deliver boxes to said elevator, means actuated by the delivery of a box onto the elevator to raise and lower said elevator, a stacking trough parallel to the path of movement of said elevator, a pair of upwardly extending arms pivotally mounted adjacent pp;- posed sides of said trough, said arms being-fn` mally resiliently urged inwardly of said trg'h and being normally in the path of movement of a box in the trough and being movable to engage a box in said trough, said arms being adaptedto be forced outwardly of said trough by the elevation of a box by said elevator to thereby permit the upward movement of said elevated box into said trough, means to force said arms outwardly of said trough to thereby release a stack of boxes and to permit lowering of the stack by said elevator, a. shiftable member mounted adjacent to one side of the trough and. a pair of toggle arms secured to the shiftable member and'to the upwardly extending arms and operable by a box in said trough for holding the arms outwardly and ing, arms pivotally mountedat the lower ends thereof to said frame, resilient means normally urging the upper ends of said arms inwardly in said trough, means actuated by the delivery of a box onto said elevator to raise and lower said elevator, said elevator being adapted to raise a box above said arms, said arms being adapted to be movedoutwardly by arising box and being adapted to move inwardly when freed to engage the lowermost box in said trough, vertically aligned guide members secured to one side of said frame and said trough, an upper and a lower rod, means resiliently connecting said rods, said rods being slidable in said guide members, a member adjustably secured to said upper rod and extending into said trough, a pair of links each pivotally secured at one end thereof to said lower rod, said links being pivotally secured at the other end thereof to said arms, the pivotal connection of said links with said rod being normally below the pivotal connections oi' said links with said arms, said horizontal member being adapted to .be engaged and raised by the uppermost box of a stack in the trough when said stack reaches a predetermined height, the movement of said horizontal member causing upward movement of said rods and moving the pivotal connection of said links with said lower rod above the pivotal connections of said links with said arms whereby said arms are forced outwardly of said trough and away Irom engagement with the boxes in said stack thus allowing said stack to be lowered by said elevator, means to maintain said rods in elevated position during the lowering of said stack, a discharge conveyor adapted to remove said lowered stack from said elevator and means -actuated by removal of a stack to lower said rods and the pivotal connection of said links with mal position.

AMBROSE NEJA, 

